Alar fold resection in 25 horses: Clinical findings and effect on racing performance and airway mechanics (1998-2013).

OBJECTIVE: To report clinical findings and performance in horses in which alar fold collapse (AFC) had been diagnosed and surgically treated and to assess form and degree of respiratory obstruction. STUDY DESIGN: Retrospective case series. ANIMALS: Twenty-one standardbreds, 2 coldblooded trotter racehorses, 1 thoroughbred, and 1 Icelandic horse. METHODS: Alar fold collapse was diagnosed on the basis of continuous abnormal expiratory flutter noise coinciding with filling of the false nostrils during exercise on a high-speed treadmill that was alleviated by suturing the alar folds (AF) temporarily in a dorsal position. In 5 cases, nasopharyngeal airway pressures were assessed. Performance after complete, bilateral AF resection was assessed by reviewing career race records and by owner or trainer telephone interviews. RESULTS: Horses presented because of poor performance, abnormal respiratory noise, or both. Additional dynamic disorders were identified in 12 of 21 standardbreds (intermittent dorsal displacement of the soft palate: n = 10; collapse of the roof of the nasopharynx: n = 2). Expiratory nasopharyngeal pressures seemed elevated in horses with AFC (range, +10.8 to +21.8 cm H2 O) compared with normal reference values. Dorsal fixation as well as complete surgical resection of the AF improved expiratory nasopharyngeal pressures to reported normal levels. At a mean of 68 months (range, 7-121) follow-up, 20 of 25 horses had competed after surgery, and 13 of 17 of the harness racehorses had established or improved their kilometer racing time marks. CONCLUSION: Alar fold collapse caused mild to moderate expiratory obstruction and may have contributed to secondary nasopharyngeal collapse in this population. CLINICAL SIGNIFICANCE: Complete surgical resection seems effective for treating AFC. Nasopharyngeal pressure measurement is a potential tool for confirming the diagnosis of AFC.

A novel approach to brachycephalic syndrome. 3. Isolated laser-assisted turbinectomy of caudal aberrant turbinates (CAT LATE).

OBJECTIVE: To describe isolated laser-assisted turbinectomy of caudal aberrant turbinates (CAT LATE) as a new minimally invasive surgical procedure for the treatment of brachycephalic dogs with obstructing caudal aberrant turbinates (CAT). STUDY DESIGN: Prospective clinical study. ANIMALS: Brachycephalic dogs (24 Pugs, 1 English Bulldog) with CAT but adequate air spaces between the lamellae of the nonobstructing ventral nasal concha. METHODS: A rhinoscopically guided diode laser fiber introduced from anterior was used to dissect CAT within the nasopharyngeal meatus, while leaving the intranasal turbinates intact. Small grasping forceps were used to extract the dissected CAT from anterior or to push it through the nasopharyngeal meatus for extraction from posterior. RESULTS: Isolated CAT LATE was successfully performed on 32 CAT in 25 dogs. Intranasally applied xylometazoline helped shrink the ventral concha, making the approach and extraction easier. Minor bleeding was the only complication observed. CONCLUSION: It is possible to remove CAT with endoscopically applied diode-laser energy while leaving the nonobstructing ventral nasal concha intact.

A Novel Approach to Brachycephalic Syndrome. 1. Evaluation of Anatomical Intranasal Airway Obstruction.

OBJECTIVE: To evaluate airway obstruction due to abnormal intranasal anatomy in 3 brachycephalic dog breeds using computed tomography and rhinoscopy. STUDY DESIGN: Prospective clinical study. ANIMALS: A total of 132 brachycephalic dogs (66 Pugs, 55 French Bulldogs, and 11 English Bulldogs) with severe respiratory distress due to brachycephalic syndrome. METHODS: Computed tomography and anterior and posterior rhinoscopy were performed to evaluate endonasal obstruction. RESULTS: All dogs had abnormal conchal growth that obstructed the intranasal airways. Rostral aberrant turbinates (RAT) were common in Pugs (90.9%) but less frequent in French (56.4%) and English (36.4%) Bulldogs. Caudal aberrant turbinates (CAT) obstructing the nasopharyngeal meatus were commonly found in all breeds (66.7%). Deviation of the nasal septum was an almost consistent finding in Pugs (98.5%) but was less common in bulldogs. Obstructing turbinates had multiple points of mucosal contact responsible for obstruction of the intranasal airway. Interconchal and intraconchal mucosal contacts were evident in 91.7% of dogs. CONCLUSION: Selective breeding for short head conformation reduces the size of the nasal cavities to such an extent that intranasal structures grow aberrantly and malformed, leading to obstructed air conducting spaces. Intranasal airway obstruction of brachycephalic dogs may contribute to their exercise and heat intolerance because of impaired pulmonary ventilation and compromised thermoregulatory functions of the canine nose. Failure to address intranasal obstruction might be an explanation for lack of therapeutic success after conventional surgery for brachycephalic syndrome. Future consideration should be given to the diagnosis, management, and treatment of this newly described aspect of airway obstruction.

A Novel Approach to Brachycephalic Syndrome. 2. Laser-Assisted Turbinectomy (LATE).

OBJECTIVE: To introduce a new surgical procedure based on interventional, laser-assisted removal of obstructing turbinate tissue to improve endonasal airway patency in brachycephalic dogs and to confirm the short and long term results using computed tomography (CT) and rhinoscopy. STUDY DESIGN: Prospective clinical study. ANIMALS: Brachycephalic dogs (n = 158; 70 Pugs, 77 French Bulldogs, 11 English Bulldogs) referred for treatment of severe respiratory distress because of brachycephalic syndrome. METHODS: Computed tomography and anterior and posterior rhinoscopy were performed to evaluate endonasal obstruction. Laser-assisted turbinectomy (LATE) using a diode laser was performed as part of a multilevel surgery. Nasal conchae that were causing airway obstruction were removed. RESULTS: The obstructing parts of the conchae were safely and efficiently removed by LATE, shaping a patent nasal airway in all dogs. The newly developed surgical procedure involved 3 steps: turbinectomy of the (1) concha nasalis ventralis; (2) rostral aberrantly growing turbinates (RAT); and (3) caudal aberrantly growing turbinates (CAT). Complications of the procedure included transient intraoperative hemorrhage in 51 of 158 dogs (32.3%); however, a temporary tamponade was necessary in only 2/158 dogs (1.3%). After 6 months, regrowth of turbinates required resection of possibly re-obstructing tissue in 25/158 dogs (15.8%; 1 Pug and 24 French Bulldogs). CONCLUSION: LATE is an effective method for creating a patent nasal airway in brachycephalic dogs with intranasal obstruction.

Ventral rhinotomy in a pet rabbit (Oryctolagus cuniculus) with an odontogenic abscess and sub-obstructive rhinitis.

A rabbit was presented for severe dyspnea and was diagnosed with an odontogenic abscess obstructing the rostral nasopharynx using CT scan and oral endoscopy. The offending tooth was extracted intraorally, but due to persistent dyspnea, an endoscopic-guided ventral rhinotomy was performed. The dyspnea subsequently resolved, but the rabbit died 5 weeks later from a seemingly unrelated cause.

Rhinotomie ventrale chez un lapin de compagnie(Oryctolagus cuniculus)atteint d'un abcès odontogène et d'une rhinite causant une subocclusion. Un lapin a été présenté pour une dyspnée grave et a été diagnostiqué avec un abcès odontogène bloquant le nasopharynx rostral par tomodensitométrie et endoscopie orale. La dent en cause a été extraite intra-oralement, mais, en raison d'une dyspnée persistante, une rhinotomie ventrale guidée par endoscopie a été réalisée. La dyspnée s'est subséquemment résorbée, mais le lapin est mort 5 semaines plus tard d'une cause apparemment non reliée.(Traduit par Isabelle Vallières).

Inside the brachycephalic nose: intranasal mucosal contact points.

The purpose of this study was to evaluate the prevalence of intranasal mucosal contact points in brachycephalic and normocephalic dogs. In total, 82 brachycephalic dogs (42 pugs and 40 French bulldogs) were evaluated by rhinoscopy for their intranasal mucosal contact and 25 normocephalic dogs were evaluated as a control group. Of those, 162 brachycephalic nasal cavities were evaluable and 140 had contact between intranasal structures (87%). Intraconchal and septoconchal mucosal contact points were the most commonly detected sites of contact. French bulldogs had a significantly higher prevalence of mucosal contact and had 3 mean contact points compared with 1.7 mean contact points per nasal cavity in pugs. Septal deviations were present in 62% of brachycephalic dogs. In the control group, mucosal contact points were present in only 7 of 50 nasal cavities (14%), and septal deviations occurred in 16% of those cases. Contact point average was 0.1 in large and 0.3 in small normocephalic dogs. Intranasal mucosal contact was identified as a common and previously unreported problem in brachycephalic dogs. Numerous contact points reduce the lumen of the intranasal passageways and indicate potential intranasal obstruction. Affected dogs might benefit from removal of obstructing conchae, potentially using laser-assisted turbinectomy.

Laser-Assisted Turbinectomy in Dogs.

This article discusses the laser-assisted turbinectomy (LATE) procedure and indications for its performance in dogs suffering from brachycephalic obstructive airway syndrome (BOAS). The article summarizes landmark works that reported, for the first time, endoscopic-assisted identification and treatment of structures within the brachycephalic nose that contribute to intranasal obstruction and resistance to breathing, specifically hypertrophic and aberrant nasal turbinates. Brachycephaly is discussed in the context of how these aberrations form and how definitive treatments such as LATE and adjunctive treatments such as ala vestibuloplasty, folded flap palatoplasty, and others may ameliorate the negative effects and improve patient outcomes associated with aberrant intranasal conchal configurations.

Retrospective evaluation of radiofrequency volumetric tissue reduction for hypertrophic turbinates in dogs with brachycephalic obstructive airway syndrome.

OBJECTIVE: The objective of this study was to retrospectively assess the effect of Radiofrequency Volumetric Tissue Reduction (RFVTR) on hypertrophic turbinates and clinical outcome in brachycephalic dogs when included in multi-level surgery (MLS). STUDY DESIGN: Clinical retrospective multicenter study. ANIMALS: 132 client-owned brachycephalic dogs. METHODS: 132 brachycephalic dogs with high-grade Brachycephalic Obstructive Airway Ayndrome (BOAS) and hypertrophic turbinates were treated with RFVTR as part of MLS of the upper airways. Intranasal obstruction was evaluated by computer tomography (CT) and antero-/retrograde rhinoscopy before and 6 months after RFVTR. The clinical records, the CT images and the rhinoscopy videos were reviewed and clinical evolution was evaluated using a standardized questionnaire. The data was scored semi-quantitatively. RESULTS: In this study, 132 patients were included for a follow-up period of 120 weeks. RFVTR resulted in minor complications, including serous nasal discharge within the first postoperative week in all dogs, and intermittent nasal congestion between 3-8 weeks after treatment in 24.3% of the patients. Rhinoscopy and CT follow-ups were available for 33 patients. Six months after treatment intranasal airspace was increased (p = 0.002) and the presence and overall amount of mucosal contact points was reduced (p = 0.039). CONCLUSION: MLS with RFVTR led to a significant reduction in turbinate volume at the 6-month follow-up examination and significant clinical improvement over a long-term period of 120 weeks. This suggests the viability of RFVTR as a turbinate-preserving treatment for intranasal obstruction in dogs with BOAS. CLINICAL SIGNIFICANCE: RFVTR is a minimally invasive turbinoplasty technique for intranasal obstruction in dogs with BOAS and can be included in MLS without increasing complication rates.

Radiographic appearance of maxillary sinus feed impaction in a horse.

A 15-year-old Belgian gelding presented in respiratory distress, with bilateral mucopurulent nasal discharge, and right-sided epistaxis. The horse had a 5-year history of dental disease and had been recently losing weight. Radiographs indicated tooth root abscessation of the right maxillary third molar tooth and probable maxillary sinus feed impaction. These findings were confirmed at surgery and necropsy. The stippled, granular radiographic appearance described here is highly characteristic of sinus feed impaction.

[Nasal obstruction: Odontogenic cysts in 4 brachycephalic dogs]. / Nasale Obstruktion: Odontogene Zysten bei 4 brachyzephalen Hunden.

OBJECTIVE: Odontogenic cysts may be of developmental or inflammatory origin. They are frequently observed in brachycephalic dogs. Due to their expansive growth, cysts in the maxilla may extend into the nasal cavity, obstruct the nasal airway and cause nasal discharge. Epithelial cysts may lead to a comparable clinical picture. A new endonasal endoscopic intervention for the removal of these cysts is described. MATERIAL AND METHODS: Four brachycephalic dogs (Boxer, Chihuahua, French bulldog, Pug) with unilateral cysts obstructing the nasal cavity were included in the study. The animals underwent clinical examination, computed tomography (CT) imaging and rhinoscopy examination. Histopathologic evaluation of the cyst wall was performed. In addition to dental surgery and conventional extraction of the involved tooth, the cyst wall was removed by endoscopic intervention via the physiologic nasal opening. Clinical course following treatment was assessed by rhinoscopy and CT. RESULTS: The main clinical signs were unilateral or bilateral serous to hemorrhagic nasal discharge. Nasal airflow was restricted in all patients. Removal of the cysts and involved teeth did not lead to any intra- and postoperative complications. No recurrence of the cysts was observed. Histologic diagnosis consisted of an epidermoid cyst, a follicular cyst, a radicular cyst, and a canine odontogenic parakeratinized cyst (COPC). Neoplastic transformation was excluded in all cases. CONCLUSIONS: Removal of the cyst wall may be performed by means of minimally invasive endoscopic intervention via the physiologic nasal entrance. The procedure is curative and carries the risk of only few complications. In cases in which treatment is restricted to extraction of the affected tooth, the nasal airway may remain obstructed due to a calcified cyst wall. CLINICAL RELEVANCE: In brachycephalic dogs, oronasal defects due to dental pathology are the most common reason for chronic nasal discharge, whereas in normocephalic dogs nasal neoplasia are. Odontogenic cysts carry importance as differential diagnosis of nasal discharge.

Evaluation of C-reactive protein, haptoglobin and cardiac troponin 1 levels in brachycephalic dogs with upper airway obstructive syndrome.

BACKGROUND: Brachycephalic dogs have unique upper respiratory anatomy with abnormal breathing patterns similar to those in humans with obstructive sleep apnea syndrome (OSAS). The objective of this study was to evaluate the correlation between anatomical components, clinical signs and several biomarkers, used to determine systemic inflammation and myocardial damage (C-reactive protein, CRP; Haptoglobin, Hp; cardiac troponin I, cTnI), in dogs with brachycephalic upper airway obstructive syndrome (BAOS). RESULTS: Fifty brachycephalic dogs were included in the study and the following information was studied: signalment, clinical signs, thoracic radiographs, blood work, ECG, components of BAOS, and CRP, Hp and cTnI levels. A high proportion of dogs with BAOS (88%) had gastrointestinal signs. The prevalence of anatomic components of BAOS was: elongated soft palate (100%), stenotic nares (96%), everted laryngeal saccules (32%) and tracheal hypoplasia (29.1%). Increased serum levels of biomarkers were found in a variable proportion of dogs: 14% (7/50) had values of CRP > 20 mg/L, 22.9% (11/48) had values of Hp > 3 g/L and 47.8% (22/46) had levels of cTnI > 0.05 ng/dl. Dogs with everted laryngeal saccules had more severe respiratory signs (p<0.02) and higher values of CRP (p<0.044). No other statistical association between biomarkers levels and severity of clinical signs was found. CONCLUSIONS: According to the low percentage of patients with elevated levels of CRP and Hp, BAOS does not seem to cause an evident systemic inflammatory status. Some degree of myocardial damage may occur in dogs with BAOS that can be detected by cTnI concentration.

[Select changes in the upper airways of the horse - an overview]. / Ausgewählte Veränderungen in den oberen Atemwegen des Pferdes - ein Uberblick.

Horses are obligate nasal breathers and depend on patency of their nasal passages. Several dynamic obstructive diseases in the pharyngeal and laryngeal area can be differentiated by high speed treadmill endoscopy and may be responsible for impaired exercise tolerance in the equine athlete. The anatomical specialty of guttural pouches predisposes the horse to species-specific diseases.

[Geometry and function of the dog nose: how does function change when form of the nose is changed?]. / Geometrie und Funktion der Hundenase: Wie ändert sich die Funktion, wenn die Form verändert wird?

Nasal airflow resistance in brachycephalic dogs is significantly elevated compared to normal dogs. LaserAssisted TurbinEctomy (LATE)-surgery as well as xylometazolin were shown to reduce pathologically increased intranasal airway resistance in brachycephalic dogs by approximately 50 %. Impulse oscillometry provides a reliable and sensitive method to examine intranasal stenoses in the canine nose. Acoustic rhinometry allows assessment of changes in cross sectional area and volume of the canine nasal cavity.

Evaluation of the repeatability of rhinomanometry and its use in assessing transnasal resistance and pressure in dogs.

OBJECTIVE: To evaluate a modified posterior rhinomanometric method for clinical application in dogs. ANIMALS: 15 healthy Beagles and 8 Bulldogs (4 healthy and 4 with respiratory problems). PROCEDURES: Rhinomanometry was performed 3 times within a 15-minute period in anesthetized dogs. Transnasal pressure (P(NA)) and nasal resistance (R(NA)) were determined by use of artificial airflow (adjusted for body weight) for inspiration (P(NAin) and R(NAin), respectively) and expiration (P(NAout) and R(NAout)). Procedures were repeated for the Beagles 7 days later. RESULTS: For the Beagles, mean +/- SD of P(NAin) for both days (0.162 +/- 0.042 kPa) was significantly lower than P(NAout) (0.183 +/- 0.053 kPa). Similarly, R(NAin) (1.47 +/- 0.41 kPa/[L/s]) was significantly lower than R(NAout) (1.64 +/- 0.46 kPa/[L/s]). Pairwise comparison of values for P(NA) and R(NA) for the 2 days revealed no significant difference. Repeatability of the method (estimated as within-day variation) for R(NA) was +/- 0.19 kPa/(L/s), whereas variation between the days was +/- 0.36 kPa/(L/s) for R(NAin) and +/- 0.44 kPa/(L/s) for R(NAout). The 4 clinically normal Bulldogs had R(NA) values ranging from 1.69 to 3.48 kPa/(L/s), whereas in the 4 Bulldogs with respiratory problems, R(NA) ranged from 9.83 to 20.27 kPa/(L/s). CONCLUSIONS AND CLINICAL RELEVANCE: R(NA) is inversely dependent on body size and nonlinearly associated with airflow. We propose that R(NA) in dogs should be determined for airflows standardized on the basis of body size. The P(NA) and R(NA) in Beagles can be measured with sufficient repeatability for clinical use and nasal obstructions are detectable.

Severe brachycephalic obstructive airway syndrome is associated with hypercoagulability in dogs.

We evaluated whether dogs with severe brachycephalic obstructive airway syndrome (BOAS) developed a hypercoagulable state similar to people with obstructive sleep apnea. Five dogs with grade 3 BOAS were included as well as 5 healthy control Labrador Retrievers. Venous blood samples were collected from each dog for performance of thromboelastography and determination of hematocrit and platelet count. Groups were compared using a t-test, with p < 0.05 considered significant. Thromboelastography results identified that all BOAS dogs were hypercoagulable compared to the Labradors, having significantly shortened clotting time with increased angle, maximal amplitude, and clot rigidity. BOAS dogs also had evidence of delayed fibrinolysis. These results are consistent with, but more severe than, those previously documented in apparently healthy Bulldogs. Together, these findings support the presence of a hypercoagulable state in brachycephalic dogs, and suggest that this state is amplified by increasing severity of BOAS.

Reflex activities of the upper airway muscles during experimental nasal occlusion in anesthetized dogs.

Reflex responses of the upper airway muscles during experimental nasal and tracheal occlusions were studied in 21 anesthetized dogs breathing through the nose or a tracheostomy (tracheal cannula). Out of them, five animals were examined for maintained negative and positive pressures applied to the isolated upper airway. When the nose was occluded at end-expiration during three consecutive breathings, the electromyographic (EMG) activity of alae nasi (AN) and posterior cricoarytenoid (PCA) muscle markedly increased. The upper airway was subjected to negative pressure, -2.41 approximately -3.04 kPa (n = 34) by these nasal occlusions. The activity of upper airway muscles was also increased by tracheal occlusions. However, such augmentation of PCA activity was much less in tracheal occlusions than nasal occlusions, whereas there was the smaller difference in AN activity between both occlusions. During nasal occlusions, a prolongation of the inspiratory time (TI) was observed. Furthermore, maintained negative pressure applied to the isolated upper airway provoked an augmentation of PCA activity. Such an augmented EMG activity of PCA and the prolongation of TI were largely diminished by sectioning the superior laryngeal nerves. These results proves that the upper airway muscles play an important role to protect the upper airway from collapsing by nasal occlusions. In addition, it is suggested that a lack of lung volume feedback is substantially concerned with the activation of AN, while negative pressure in the upper airway is essential to stimulate PCA.

Cystic nasal concha in a calf.

Unilateral cystic nasal concha was diagnosed in a 6-month-old Brangus male calf by use of endoscopy, radiography, and histologic examination. Cystic nasal conchae have been excised via dorsolateral rhinotomy, but the lesion in the calf of this report was excised transnasally, with considerable ease, using obstetric wire. Postoperative complications did not develop, and the calf was reportedly in good health 3 months after discharge.

Alar fold resection in horses: 24 cases (1979-1992).

Between 1979 and 1992, the alar folds were resected bilaterally in 22 horses and unilaterally in 2 horses. Abnormal respiratory tract noise and exercise intolerance were the primary complaints prior to surgery. Significantly (P = 0.01) more Standardbreds underwent resection of the alar folds, compared with the number of Standardbreds in the hospital population during the same period. The alar folds palpated abnormally thick in 13 horses and normal in 11 horses. Temporary dilatation of the nares with mattress sutures or clips lessened the respiratory tract noise and improved exercise tolerance in all 8 horses in which the diagnostic test was performed. Manual elevation of the alar folds reduced respiratory noise in the 11 horses evaluated. Long-term follow-up evaluation by telephone was available for 14 horses. All surgical incisions had healed cosmetically. Respiratory tract noise was decreased, and exercise tolerance improved in 10 of 14 (71%) horses. Complete charted racing information was obtained for 16 horses. Fourteen horses started their first race a mean of 118 days (range, 13 to 321 days) after surgery. The mean number of starts after surgery was 51, with 14 of 16 (88%) horses starting more than 6 times after surgery. Of the 16 horses, 8 horses raced at least 3 times before and after surgery; 4 had improved racing performance, 2 had similar performance, and 2 had decreased performance. Five Standardbreds never raced, and 1 Standardbred raced once before surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Nasal obstruction caused by nutritional osteodystrophia fibrosa in a group of Ethiopian horses.

A severe, advanced case of nutritional osteodystrophia fibrosa is described in a 10-year-old gelding with primary upper respiratory obstruction and chronic weight loss, which was one of a group of similarly affected horses in Ethiopia. The diagnosis was based on the clinical signs, gross lesions, histopathology and management history. The affected bones had suffered severe mineral depletion.

Alapexy: an alternative technique for repair of stenotic nares in dogs.

Alapexy involves the creation and apposition of two small elliptical incisions, which fix the alae in an abducted position. Permanent alapexy was achieved in four of five dogs (eight of nine nostrils) that were operated. Four animals had significant improvement in their respiratory efforts because of reduced nasal obstruction. Although the alapexy procedure was somewhat more difficult to perform than simple wedge resection techniques, it may be a viable option in those animals where other techniques have failed or in animals that have dystrophic or flaccid alar cartilage. The alapexy technique may also improve the diameter of the nares compared to previously described techniques.